Dr. Ballard and colleagues have carried out a study to determine the effect of inhaled nitric oxide on oxygenation in infants with severe, ventilator dependent bronchopulmonary dysplasia (BPD). Twenty-seven preterm (23-32 weeks gestational age) infants, age 4 weeks to 7 months have been enrolled to date. Oxygen requirements ranged from 45% to 100%. In 19 of 26 treatment courses there was a significant increase in PaO2 after 1 hour of nitric oxide. The median change in PaO2 was 24 mmHg (range -15 to + 112; p < .01). Following 3 days of nitric oxide, 20 infants had > 15% reduction in FiO2, and 14 of the 20 had > 35% reduction (p < .01).